M52B28 oversized piston Options

[jsmit428]

I am tearing down my 98 328i for a refresh and found some scoring on the cylinder walls and suspect I’m gonna need new pistons. What are options? Putting on M 50 intake and S 52 cams and headers mild build by my standards

[pbonsalb]

A few companies make aftermarket pistons. Off the shelf versions are for overboring stock motors by 10-20 thousandths and typically are offered in forced induction CR of 8.5 to 9.0 to 1 and naturally aspirated performance CR of around 11.3:1. Wiseco, Mahle, JE, and others for M52/S50/S52 with 135mm rods (stock is 135mm).